1. Field of the Invention
The invention concerns a gas cooled nuclear reactor with several loops connected with the core by means of channels, with heat absorbing components such as heat exchangers, split tubular furnaces or the like being arranged in the loops with hot gas flowing through said components from bottom to top and their external surfaces being exposed to cold gas.
2. Background of the Prior Art
In nuclear reactor installations, the thermal energy produced in the reactor core is transferred by means of a cooling gas medium to heat absorbing components such as heat exchangers, split tubular furnaces, and the like, which may be arranged in circuits or loops. A circuit or loop consists of a shaft or pod in the form of a cylinder arranged vertically in the prestressed concrete pressure vessel connected with the core by means of one or several channels. The circuit or loop houses different reactor components such as the heat exchanger equipment and the like. The cooling medium for example (helium) flows through the core from top to bottom. The cooling medium is conducted through a hot gas channel to the heat absorbing components, wherein it discharges a substantial portion of its thermal energy. It is then passed to the blower and returned to the core, whereby the cooled gas usually flows along the outside of the heat absorbing components. The above-described gas circuit may be supplemented by means of further reactor components, for example, a gas turbine. A plurality of circuits or loops are utilized in the conventional high temperature, gas cooled nuclear reactor.
An essential characteristic of a nuclear reactor installation is that it is designed for a predetermined operational state. Excessive temperatures over extended periods of time or extreme fluctuations around its mean value may result in damage to the reactor installation. Grave problems are associated with the failure of certain heat absorbing components (such as with split tubular furnaces), as access to them is not possible for operational reasons alone (operational at gas temperatures of around 900.degree. C.).